1. Field of the Invention
The present invention relates in general to non-woven paper compositions, and more particularly, to thermally stable, non-woven, paper compositions, which are fabricated at least in part from poly(para-phenylene-2,6-benzobisoxazole) and thermally stable derivatives thereof.
2. Background Art
To the best of Applicant's knowledge, stone was utilized as the first medium to record human activity and/or history. Years later, bark, leaves, and ivory were utilized as advanced mediums to record human activity because of, among other things, their beneficial weight properties—compared to stone. Historians have further indicated that sometime between approximately 2500 B.C. and 2000 B.C., the manufacture of writing paper (in a crude form as we know it today) initiated from utilization of a tall reed growing along the Nile River in Egypt called papyrus; hence the name paper. Historians have also indicated that other early writing materials were dried calf and goatskin parchment, wax-covered boards believed to be used by the Romans, and clay-brick records believed to be preserved from Babylonian times.
To the best of Applicant's knowledge, the actual manufacture of paper was invented by the Chinese sometime around 100 A.D., but it was not until the end of the fourteenth century that the manufacturing process had undergone material improvements in southern Europe. The paper industry did not obtain a firm foothold in England until the seventeenth century.
Around 1750, the Hollander Beater was developed for the purpose of making paper. In 1799, a Frenchman, Louis Robert, invented a process for forming a sheet of paper on a moving wire screen. This machine is known today as the Fourdriner machine. The Fourdriner process came to the Americas in 1844. Using the Fourdriner machine, an American Chemist Tilghman was granted a United States Patent (U.S. Pat. No. 70,485) for the sulfide process. Later the sulfate, or Kraft process, was developed by Dahl around 1884 in Danzig, Germany. In 1904 the Kraft paper making process was adopted in America and remains, to this day, a dominant method for manufacturing cellulose based papers.
As the demand for the volume of paper grew in the industrial age, so did the demand for enhanced physical properties of paper. In the 1960's, E. I. Du Pont de Nemours and Company answered some of the commercial demands for enhanced physical properties by incorporating non-rigid synthetic fibers into paper (see U.S. Pat. No. 2,999,788).
Notwithstanding the distinct and continuous historical advancements in recording human activity and/or history, which very recently (historically speaking) has utilized paper, there remains a strong commercial demand for continued enhancements in the physical properties of paper. For example, one substantial drawback associated with even the newer synthetic papers is their lack of comprehensive thermal stability and strength—among many other characteristics. Indeed, the demand for a thermally stable paper and associated products that can acceptably withstand substantial exposure to elevated temperatures remains strong, and, to the best of Applicant's knowledge, unsatisfied. Moreover, conventional synthetic papers also lack comprehensive strength and therefore require, in many applications, additional undesirable amounts of paper—which can materially increase weight.
It is therefore an object of the present invention to provide thermally stable, non-woven, paper compositions, which are fabricated at least in part from poly(para-phenylene-2,6-benzobisoxazole) and thermally stable derivatives thereof which satisfy at least some of the present commercial demand for paper and associated products having enhanced physical properties.